The pertinent staff members, which in this case are most of our regulars, are in a meeting about the big case -- their patient is a baby in utero whose heart is growing outside his body. Very few cases have ever been recorded and even fewer survived, so it's a pretty Big Deal. Addison tells them that she had a case like this ten years earlier where the baby squeezed his own heart in utero and died. They go over some possible complications and Hahn tells her they've got a lot of work ahead, but they have a rah-rah moment when Addie asks if she's up for it and she replies, "Always." Mark tries to get in on that action by reminding them about the skin-growing, but it only makes Alex look at him like he's a doofus. A really hot doofus, but a doofus nonetheless.
George comes into the clinic and as he passes Izzie's interns, the air is thick with inside jokes. Izzie had paged him so that she could make him feel guilty for having a party without inviting her -- she apparently spent her evening googling recipes. (As someone who has gotten caught up for hours reading up on random subjects on Wikipedia, I can't throw stones here. I also don't think it sounds like such a terrible evening.) George points out that he didn't think Izzie would want to spend an evening hanging out with the interns and seems torn between feeling like he has to explain himself and feeling cool and confident with a new group of friends. A new group with a horrible inside joke that involves telling someone they "coded," complete with hand signals. But while I hate most of these interns and the joke is annoying, it's nice to see George not acting like a kicked puppy, and it's also nice to see something annoy Izzie so badly. Lexie bounds up to tell George they're all set for that night, and at Izzie's questioning they admit the interns are having a darts tournament at Joe's. Izzie totally tries to push her way into the plans, so George asks meekly if she'd like to come. She happily agrees and as they walk away, Lexie informs him, "You SO coded."
Addie sits down with Bailey and tells her that she thought it would be weird to come back, but that it's "strangely comforting" to find everything the same. It's a little bit strangely un-comforting that Addison has turned into a dolt, though. She tells Bailey that in L.A., they actually talk about things while in Seattle no one says anything and she's supposed to guess what's up from a raised eyebrow. (We all hold hands and sing in L.A., too, after we've shared all of our deepest feelings.) Addie seems to have shed a bit of her idiocy and has noticed that's something wrong with Bailey, but Bailey doesn't want to tell her what's wrong and just insists on saying that a lot has changed. When Addie asks, Bailey gives the examples that the clinic is making money now, Adele left Richard, and Derek and Meredith broke up. She's about to mention her own separation but Addie is too distracted by the demise of the worst super-couple in the history of television.